In the field of packaging sliced comestible products such as meat, luncheon meat, and cheese using high speed packaging and slicing equipment, it is highly desirable to transfer the sliced product quickly form the slicer to the packaging machine to avoid contamination of the product. Generally speaking, modern packaging machines operate optimally at a uniform high speed, whereas slicing machines, although swift, have an inherently erratic output. This is due to the fact that the comestible product being sliced often comprises a loaf or a large piece of meat, and there is a hiatus in the output between the end of one piece and the commencement of the subsequent piece. Also, the sliced product is generally placed in stacks each of uniform number of slices, each stack being weight checked. Due to the fact that the packages typically are labeled with a predetermined net weight, the stacks must meet strict weight tolerances. Those stacks that do not meet the weight tolerances are removed from the packaging line conveyor. Thus the slicer loading and the stack weight check cause the ultimate slicer output rate to vary considerably.
Ideally, the conveyor from the slicer should deliver stacks to the packaging machine at a rate exactly matched to the packaging machine rate of loading and sealing the packages. When the slicer is operating optimally, stacks are deposited on the conveyor at regularly spaced intervals, and the conveyor travels at a constant speed to deliver the stacks at the proper rate to the packaging apparatus. However, the slicer loading factor and the weight check procedure occasionally result in removal of a stack from its place on the conveyor, resulting in a vacant spot on the conveyor. Without some remedial apparatus, the vacant spot will travel to the packaging apparatus, the respective package will not be filled, and the packaging apparatus will produce a sealed, empty package.
There are known in the prior art many forms of accumulator devices which detain a number of stacks on some form of storage device interposed in the conveyor line, and deliver each stack serially upon demand from the packaging apparatus. In such accumulators, it is generally necessary to quickly accelerate and stop the stacks entering and leaving the storage area. Due to the intrinsically fragile nature of the stacks of slices, such rough treatment can often result in damage to the stacks which renders them unsuitable for packaging. For example, the stacked may become skewed, the bottom slice may become dislodged or damaged during the acceleration or deceleration, or the like.